In the Baroque surroundings of St Antonino – a short walk from St Mark's Square – the unusual display encourages visitors to peer inside the mysterious boxes to see what might be inside.

Like a twisted doll house turned into a Chinese prison, the sculptures are scenes from his detention with the artist shown going about his daily tasks with two guards present all the time.

In one he is sleeping as guards watch, then he is naked in the shower, pacing in his cell, eating a meal, talking and going to the toilet.

The impression is of an overwhelming attack on the artist's intimacy that immediately puts visitors ill at ease as they peer like voyeurs.

The realism of the works echoes the traditional aesthetic of the communist country – rendered all the more unusual in the context of a church.

The choice of a house of worship could be another gesture of provocation from Ai since China has difficult relations with the Catholic Church.

The six boxes, which are around 1.5 metres (five feet) high and 3.5 metres long, have a sobriety that fits with the church's theatrical elegance.

The exhibition entitled "S.A.C.R.E.D" was installed by the Lisson Gallery (www.lissongallery.com), based in London and Milan, and can be viewed until September 15th.

"It is a personal statement and a political statement," Greg Hilty, curatorial director of the gallery, told AFP.

"It was a very traumatic experience for him. He needed to exorcise the trauma," he said.

"It is about a man's search for identity," he said.

Ai has emerged as a fierce critic of the government in Beijing, often through his prolific use of the Internet and involvement in sensitive social campaigns.

He was detained for 81 days in 2011 during a roundup of activists at the time of the Arab Spring popular uprisings, and on his release he was accused of tax evasion and barred from leaving the country for one year.

The Chinese artist, who cannot be in Venice, because he has still not been returned his passport, described his detention in a video message published on his site last week.

The video showed Ai under interrogation, marking a document with a red thumbprint and wearing a black hood labelled "Criminal" before being scrutinized by guards in the prison shower.

Ai told AFP in Beijing that for the video he created an "exact model" of the room in which he was kept for much of the period.

"There are so many political prisoners in China who are being kept in even worse conditions than I was," he said. "When I was detained, the guards would ask me to sing songs for them… even in such a place people still have imagination."